<Styles xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Style Selector="Expander /template/ ToggleButton#PART_toggle">
        <Setter Property="Template">
            <ControlTemplate>
                <Border BorderThickness="0">
                    <Grid ColumnDefinitions="Auto,Auto">
                        <Border Grid.Column="0" Width="20" Height="20"
                                HorizontalAlignment="Center" 
                                VerticalAlignment="Center">
                            <Path Fill="#ffffff"
                                  HorizontalAlignment="Right"
                                  VerticalAlignment="Center"
                                  Data="M 0 2 L 4 6 L 0 10 Z" />
                        </Border>
                        <ContentPresenter Name="PART_ContentPresenter"
                                          Grid.Column="1" 
                                          Background="Transparent" 
                                          Content="{TemplateBinding Content}" 
                                          VerticalAlignment="Center" 
                                          HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                                          VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                                          Padding="{TemplateBinding Padding}"/>
                    </Grid>
                </Border>
            </ControlTemplate>
        </Setter>
    </Style>
    <Style Selector="Expander">
        <Setter Property="Margin" Value="0" />
    </Style>
    <Style Selector="Expander /template/ ContentPresenter">
        <Setter Property="Background" Value="{DynamicResource ThemeCardBrush}" />
    </Style>
    <Style Selector="Expander /template/ ToggleButton#PART_toggle /template/ Border">
        <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush}" />
    </Style>
    <Style Selector="Expander /template/ ToggleButton#PART_toggle:pointerover /template/ Border">
        <Setter Property="BorderBrush" Value="Transparent" />
    </Style>
    <Style Selector="Expander:down:expanded /template/ ToggleButton#PART_toggle /template/ Path">
        <Setter Property="Fill" Value="#ffffff" />
    </Style>
    <Style Selector="Expander /template/ ToggleButton#PART_toggle TextBlock">
        <Setter Property="Foreground" Value="#ffffff" />
    </Style>
</Styles>